【HDOJ】1495 非常可乐

bfs.

 #include <iostream>
 #include <queue>
 #include <cstdio>
 #include <cstring>
 using namespace std;

 #define MAXN 105

 bool visit[MAXN][MAXN][MAXN];

 typedef struct node_t {
     int x[];
     int t;
     node_t() {}
     node_t(int xx, int yy, int ss, int tt) {
         x[] = xx;
         x[] = yy;
         x[] = ss;
         t = tt;
     }
 } node_t;

 int s, m, n;

 bool check(node_t d) {
     int half = s>>;

     if ((d.x[]==half) && (d.x[]== || d.x[]==)) return true;
     if ((d.x[]==) && (d.x[]==half)) return true;

     return false;
 }

 int bfs() {
     if (s & )
         return -;
     queue<node_t> Q;
     int x[] = {m, n, s};
     int i, j, k, tmp;

     memset(visit, false, sizeof(visit));
     visit[][][s] = true;
     Q.push(node_t(,,s,));

     while (!Q.empty()) {
         node_t d = Q.front();
         Q.pop();
         for (i=; i<; ++i) {
             for (j=; j<; ++j) {
                 if (i == j)
                     continue;
                 node_t dd = d;
                 // from i to j
                 tmp = x[j] - dd.x[j];
                 if (tmp > ) {
                     if (dd.x[i] > tmp) {
                         dd.x[j] = x[j];
                         dd.x[i] -= tmp;
                     } else {
                         dd.x[j] += dd.x[i];
                         dd.x[i] = ;
                     }
                 }
                 if (visit[dd.x[]][dd.x[]][dd.x[]]) {
                     continue;
                 }
                 ++dd.t;
                 visit[dd.x[]][dd.x[]][dd.x[]] = true;
                 if ( check(dd) )
                     return dd.t;
                 Q.push(dd);
             }
         }
     }

     return -;
 }

 int main() {

 #ifndef ONLINE_JUDGE
     freopen("data.in", "r", stdin);
 #endif

     while (scanf("%d%d%d",&s,&m,&n)!=EOF && (s||m||n)) {
         int ans = bfs();
         if (ans > )
             printf("%d\n", ans);
         else
             printf("NO\n");
     }

     return ;
 }